It is interesting to look at the new situation on the Korean Peninsula and, in particular, America’s relationship with the various parties there -- South Korea, North Korea, China, Japan and even Russia -- in light of the election last week of relatively liberal Moon Jae-in as president of South Korea. He succeeds the more conservative President Park Geun-hye, ousted in March.

Moon, the flag-bearer of the Democratic Party, won in a field of 13 candidates, the first liberal to occupy presidency in 10 years. The issues in the contest included, naturally, the economy, which is reasonably healthy in spite of rising unemployment. Security was a second issue, underlined by missile launchings (the latest was Sunday) and other militant actions undertaken in North Korea under Kim Jong-un.

A third issue was relations with the United States, an eternal question since South Korea’s independence in 1948. It was significant as the Trump administration goes through its teething period of figuring out what America’s posture should be in East Asia and South Korea’s role in that policy.

Moon has pledged to swing South Korea’s approach to North Korea, in spite of Kim’s sometimes thunderous threats, toward a “Sunshine Policy.” This is a South Korean approach that suggests it is directed toward reunification of the Korean Peninsula. It has in the past included economic incentives, such as a South Korean business zone established across the border in the North, accompanied by inconspicuous economic aid to the poorer communist nation.

China also plays an important role. North Korea depends abjectly on Chinese help, with energy, rice and trade. China is also South Korea’s most important trading partner, taking the lion’s share of its exports and providing the largest share of its imports. The Chinese have begun squeezing the South Koreans through boycotts of their exports since the United States began installing in South Korea a missile defense system, the Terminal High Altitude Area Defense System, which the Chinese claim is capable of targeting them as well as North Korea and, thus, destabilizing.

America could potentially spend less on Korean problems, including for the $1 billion THAAD system, visiting US Navy aircraft carrier battle groups and joint exercises with South Korea and Japan, if Moon’s “Sunshine Policy” gained some traction.